Why a calendar is not momentarily available
In all my calendars the status is "The calendar is not momentarily available". This was also the situation before I updated the newest versions of Mozilla and Lightning. Cookies are on. I reset also the password relating to the calendar. After that Google asked password again. It seems that the problem is in the server handling the calendar?
Wšě wotmołwy (3)
I have the same problem. Making an appointment gives an error: Modification failed. On the other hand, synchronizing from Gmail does work. (I didn't use the Google Calendar, but the ICS-option.
A strange thing is that when I was triying to make a new calendar, the option Google calendar was missing in the pop-up window. Only the options iCalendar, CalDAV and WCAP are available. So it is also impossible to make a link tot the Google Calendar.
Wot FredV změnjeny
My problem is solved. Uninstall 'Provider for Google Calendar' and reinstall the Provider solved my problem. More in this thread: https://support.mozilla.org/nl/questions/1024370?page=3#answer-640567
Now my Mozilla connection to Google calendar is again working - by doing no changes in my site. The problem was somewhere else.